xref: /openbmc/linux/arch/arm/kernel/sleep.S (revision 95e9fd10)
1#include <linux/linkage.h>
2#include <linux/threads.h>
3#include <asm/asm-offsets.h>
4#include <asm/assembler.h>
5#include <asm/glue-cache.h>
6#include <asm/glue-proc.h>
7	.text
8
9/*
10 * Save CPU state for a suspend.  This saves the CPU general purpose
11 * registers, and allocates space on the kernel stack to save the CPU
12 * specific registers and some other data for resume.
13 *  r0 = suspend function arg0
14 *  r1 = suspend function
15 */
16ENTRY(__cpu_suspend)
17	stmfd	sp!, {r4 - r11, lr}
18#ifdef MULTI_CPU
19	ldr	r10, =processor
20	ldr	r4, [r10, #CPU_SLEEP_SIZE] @ size of CPU sleep state
21#else
22	ldr	r4, =cpu_suspend_size
23#endif
24	mov	r5, sp			@ current virtual SP
25	add	r4, r4, #12		@ Space for pgd, virt sp, phys resume fn
26	sub	sp, sp, r4		@ allocate CPU state on stack
27	stmfd	sp!, {r0, r1}		@ save suspend func arg and pointer
28	add	r0, sp, #8		@ save pointer to save block
29	mov	r1, r4			@ size of save block
30	mov	r2, r5			@ virtual SP
31	ldr	r3, =sleep_save_sp
32#ifdef CONFIG_SMP
33	ALT_SMP(mrc p15, 0, lr, c0, c0, 5)
34	ALT_UP(mov lr, #0)
35	and	lr, lr, #15
36	add	r3, r3, lr, lsl #2
37#endif
38	bl	__cpu_suspend_save
39	adr	lr, BSYM(cpu_suspend_abort)
40	ldmfd	sp!, {r0, pc}		@ call suspend fn
41ENDPROC(__cpu_suspend)
42	.ltorg
43
44cpu_suspend_abort:
45	ldmia	sp!, {r1 - r3}		@ pop phys pgd, virt SP, phys resume fn
46	teq	r0, #0
47	moveq	r0, #1			@ force non-zero value
48	mov	sp, r2
49	ldmfd	sp!, {r4 - r11, pc}
50ENDPROC(cpu_suspend_abort)
51
52/*
53 * r0 = control register value
54 */
55	.align	5
56	.pushsection	.idmap.text,"ax"
57ENTRY(cpu_resume_mmu)
58	ldr	r3, =cpu_resume_after_mmu
59	instr_sync
60	mcr	p15, 0, r0, c1, c0, 0	@ turn on MMU, I-cache, etc
61	mrc	p15, 0, r0, c0, c0, 0	@ read id reg
62	instr_sync
63	mov	r0, r0
64	mov	r0, r0
65	mov	pc, r3			@ jump to virtual address
66ENDPROC(cpu_resume_mmu)
67	.popsection
68cpu_resume_after_mmu:
69	bl	cpu_init		@ restore the und/abt/irq banked regs
70	mov	r0, #0			@ return zero on success
71	ldmfd	sp!, {r4 - r11, pc}
72ENDPROC(cpu_resume_after_mmu)
73
74/*
75 * Note: Yes, part of the following code is located into the .data section.
76 *       This is to allow sleep_save_sp to be accessed with a relative load
77 *       while we can't rely on any MMU translation.  We could have put
78 *       sleep_save_sp in the .text section as well, but some setups might
79 *       insist on it to be truly read-only.
80 */
81	.data
82	.align
83ENTRY(cpu_resume)
84#ifdef CONFIG_SMP
85	adr	r0, sleep_save_sp
86	ALT_SMP(mrc p15, 0, r1, c0, c0, 5)
87	ALT_UP(mov r1, #0)
88	and	r1, r1, #15
89	ldr	r0, [r0, r1, lsl #2]	@ stack phys addr
90#else
91	ldr	r0, sleep_save_sp	@ stack phys addr
92#endif
93	setmode	PSR_I_BIT | PSR_F_BIT | SVC_MODE, r1  @ set SVC, irqs off
94	@ load phys pgd, stack, resume fn
95  ARM(	ldmia	r0!, {r1, sp, pc}	)
96THUMB(	ldmia	r0!, {r1, r2, r3}	)
97THUMB(	mov	sp, r2			)
98THUMB(	bx	r3			)
99ENDPROC(cpu_resume)
100
101sleep_save_sp:
102	.rept	CONFIG_NR_CPUS
103	.long	0				@ preserve stack phys ptr here
104	.endr
105